When you’re trying to slim down, you want to lose body fat, not muscle. To preserve and tone your muscle mass, you need a regular program that combines dietary approaches with physical activity. Neglecting one or the other – diet or exercise – may not yield the results you’re looking for. Check with your doctor before starting any new diet or exercise program to make sure it’s safe for you.
Principles of Fat Loss
The general formula for losing fat is to do so slowly, trimming down by 1 or 2 pounds a week. To do this, you need to create a calorie deficit of 500 to 1,000 calories a day. That’s a lot of calories to eliminate from your diet, and dangerously low calorie counts can actually work against you by slowing down your metabolism and making fat loss more difficult. Women shouldn’t consume fewer than 1,200 calories a day, and men shouldn’t let their calories dip below 1,800.
If cutting 500 to 1,000 calories puts you below these minimum counts, reduce your daily intake by 250 calories instead and burn another 250 through exercise. A 155-pound person can burn 250 calories with 30 minutes of various kinds of exercise, such as low-impact step aerobics, stationary cycling, rowing, ice skating or tennis.
Diet for Fat Loss
Make your calories count by choosing unprocessed whole foods like fruits and vegetables, whole grains and lean protein. Fruits, vegetables and whole grains contain fiber that helps keep you feeling full so you can reduce your overall calorie intake. In addition, whole grain consumption reduced both body weight and body fat over the course of 12 weeks in a study of overweight older women published in the Journal of Nutrition in 2012. Choose whole wheat bread and pasta over refined white versions, and add more foods like quinoa, brown rice and millet to your regimen.
Foods containing protein are thermogenic, meaning they actually require more energy to eat, and are highly satiating, keeping you full so you can meet your calorie deficit. Go for heart-healthy plant-based protein from soy, legumes and nuts, or leaner animal sources like fish and poultry, and combine it with plenty of non-starchy, fiber-rich vegetables like broccoli, bell peppers and green beans. A protein intake of 30 percent of calories reduced the appetite, body weight and fat mass of subjects better than a 15 percent protein intake in a study published in the American Journal of Clinical Nutrition in 2005.
It’s a myth that you need to trim fat from your diet in order to lose body fat. When choosing fats, though, limit intake of the saturated fat in red meat and full-fat dairy to reduce your risk of cardiovascular issues, and avoid the trans fats in foods like prepared baked goods. Opt instead for unsaturated fats like those found in fish, nuts, seeds and avocado.
Fat Loss With Exercise
It’s hard to create a significant enough calorie deficit through diet alone, but adding cardio to burn calories plus resistance training to tone your body help you meet your goal. The American College of Sports Medicine recommends at least 30 minutes of moderate-intensity exercise – enough to break into a sweat but still be able to talk -- five days a week, like brisk walking, running, cycling or using cardio machines at the gym. Also do two days a week of resistance training, such as free weights, resistance bands or weight machines for eight to 12 repetitions of eight to 10 different exercises targeting all your major muscles, says ACSM.
You may see greater results in fat loss if you combine higher protein intake with intense cardio exercise and resistance training, according to a study published in the American Journal of Clinical Nutrition in 2016. The male subjects in the study who ate more protein and engaged in high-intensity interval training, or HIIT, plus resistance exercise most days retained more lean body mass and lost more fat than those who ate half the protein but did the same amount of exercise. HIIT consists of short periods – 5 to 8 minutes – of intense workouts, followed by similarly timed “relief” periods of about half the intensity, for up to 60 minutes of exercise.
Fat Loss Supplements
A number of supplements claim to help with fat loss by promoting fat burning, but these often come with safety concerns and show little clinical evidence of effectiveness. One supplement that has shown some promise is conjugated linoleic acid or CLA, a type of fatty acid. In one clinical study, overweight participants who took CLA reduced their body fat mass over the course of 24 months of supplementation without adverse effects. The results appeared in the Journal of Nutrition in 2005. An earlier study found that CLA reduced body fat, but not body weight, in healthy individuals when combined with 90 minutes of exercise three times weekly. The authors published their results in the Journal of International Medical Research in 2001.
Talk to your doctor about whether CLA might be a good choice for you. While no safety concerns are on record, possible side effects include abdominal pain, constipation, diarrhea and increased serum cholesterol levels.
- American College of Sports Medicine: Metabolism is Modifiable with the Right Lifestyle Changes
- Nutrition and Metabolism: A High-protein Diet for Reducing Body Fat
- American Journal of Medicine: Dietary Fat Is Not a Major Determinant of Body Fat
- American College of Sports Medicine: High Intensity Interval Training
- American Journal of Clinical Nutrition: Higher Compared With Lower Dietary Protein During an Energy Deficit Combined with Intense Exercise Promotes Greater Lean Mass Gain and Fat Mass Loss
- NIH: Dietary Supplements for Weight Loss
- Journal of Nutrition: Supplementation With Conjugated Linoleic Acid for 24 Months Is Well Tolerated by and Reduces Body Fat Mass in Healthy, Overweight Humans
- Journal of International Medical Research: Conjugated Linoleic Acid Reduces Body Fat in Healthy Exercising Humans
- Journal of Nutrition: Whole Grain Compared With Refined Wheat Decreases the Percentage of Body Fat Following a 12-week, Energy-restricted Dietary Intervention in Postmenopausal Women